Physicians have used elastic ligating bands to treat lesions, including internal hemorrhoids and mucositis and for performing mechanical hemostasis. The object of such ligation is to position a ligating band, which is usually elastic, over the targeted lesion or blood vessel section by first stretching the band beyond its undeformed diameter and then drawing the tissue to be ligated within the band. Thereafter the band is released so that it contracts, applying inward pressure on the section of tissue caught within the band. The effect of the inward pressure applied by the band is to stop all circulation through the targeted tissue, thereby causing the tissue to die. The body then sloughs off the dead tissue or the dead tissue may be aspirated into an endoscope or a similar device.
Previous ligating band dispensers allowed a user to dispense only a single ligating band at a time. That is, after a single ligating band was dispensed, if a user wanted to ligate another portion of tissue, the user would remove the device from the patient's body, load a new ligating band on the device and reinsert the device to the desired area within the patient's body.
U.S. Pat. No. 5,398,844 to Zaslavsky et al. ("the Zaslavsky patent"), expressly incorporated herein by reference, describes a ligating band dispensing device including a substantially cylindrical support surface over which elastic ligating bands are stretched. The cylindrical support surface is typically attached to the distal end of an endoscope which is advanced into the body to a target area. A user then applies suction through the endoscope to draw the tissue to be ligated into the cylindrical support surface and releases a ligating band to contract around the tissue. While the device of the Zaslavsky patent allows a user to place several ligating bands at desired locations without removing the device from the patient's body to reload ligating bands, it requires multiple pull strings to deploy the ligating bands. These pull strings may interfere with each other or become tangled. In addition, as the number of ligating bands included on the distal end of these devices has been increased, the number of pull strings increases while the dispenser itself elongates. Accordingly, the field of vision from the endoscopes to which these devices are normally coupled has been correspondingly decreased.